JPH0724784Y2 - Screw drop prevention terminal - Google Patents

Description

[Detailed Description of the Invention] (Field of Use of the Invention) The present invention relates to a screw drop prevention terminal suitable for use in electric equipment such as an electronic watt hour meter and suitable for connecting an electric wire with a round crimp terminal. It is about improvement.

(Background of the invention) Generally, when connecting electrical equipment or switchboards to each other, use a round crimp terminal crimped to the end of the wire to prevent problems such as disconnection due to unexpected pulling force. Connection is made by pressing the terminal fittings with the terminal screws.

In this case, when inserting the crimp terminal into the crimping position of the terminal fitting, as a matter of course, float or remove the terminal screw for crimping the crimp terminal from the surface of the terminal fitting by more than the thickness of the crimp terminal. Therefore, in general, the terminal screw is once removed from the terminal fitting, the crimp terminal is brought into contact with the pressure contact position of the terminal, and then the terminal screw is screwed into the terminal fitting again to make the connection.

As described above, since the conventional terminal screw is once removed from the terminal fitting, the workability is extremely poor especially in a narrow working environment where both hands cannot be used freely and the terminal screw is not suitable. When the terminal screw is once removed from the terminal, the operator may drop the terminal screw and drop it.

This is because when the terminal screw is removed from the terminal fitting to connect the round crimp terminal, the terminal screw is completely free from the terminal. There is also a terminal provided with a mechanism for preventing the terminal screw from falling off when it becomes free.

FIG. 10 shows an example of a conventional screw dropout prevention terminal.

This is a terminal for relaying electric wires in a control panel or the like. This screw drop prevention terminal 1 is formed by an electrically insulating material, and an engaging portion 3 provided at the lowermost portion of a terminal base portion 2 is used for the terminal shown in FIG. It is used by forming a terminal group by inserting a required number of rail-like mounting members 11 as shown in FIG.

In the front view of the conventional screw dropout prevention terminal of FIG. 10,
The lowermost engaging portion 3 of the screw drop prevention terminal 1 is shown as engaged with the rail-shaped mounting member 11 shown in FIG.

The terminal screw 4 of the screw drop prevention terminal 1 is screwed into the terminal fitting 5 to press-contact the crimp terminal 6. Crimp terminal 6
When the terminal screw 4 is loosened to insert the terminal screw 4 into the press-fitting position of the terminal fitting 5, the lower end of the terminal screw 4 leaves the female screw portion 7 of the terminal fitting 5, and at the same time, the terminal screw holder 8 that supports the terminal screw 4 moves the coil The elasticity of the spring 9 pushes the arm 10 provided at the lower part of the spring 9 and raises the arm 10 by a certain distance along the wall surface of the terminal base 2, so that the crimp terminal 6 is provided between the terminal screw 4 and the terminal fitting 5. Make enough clearance to insert.

However, such a conventional screw dropout prevention terminal 1 has a considerably complicated structure for preventing the terminal screw 4 from falling off, which makes the overall shape of the terminal large and the price thereof expensive. Preventing the terminal screws from falling off economically with a simple structure has been one of the problems to be solved in order to improve the efficiency of the wiring work of electric devices.

(Object of the Invention) An object of the present invention is to solve the above-mentioned problems and to provide an economical screw drop prevention terminal capable of completely preventing the terminal screw from falling off with an extremely simple structure.

(Features of the Invention) In order to achieve the above object, the present invention forms a male screw portion having a screw pitch larger than the screw pitch of the terminal screw on the head of the terminal screw, and attaches it to the terminal so as to cover the upper side of the terminal fitting. The terminal screw holder to be mounted has a female screw hole that has an internally deformable 1-pitch female screw screwed into the male screw part of the terminal screw head, and the relative relationship between the female screw hole of the terminal screw holder and the terminal fitting. The position is set such that the terminal screw is screwed into both the terminal fitting and the female screw hole of the terminal screw holder in the process of removing the terminal screw from the terminal fitting.

(Embodiment of the Invention) FIG. 1 is a perspective external view of an electronic watt-hour meter having a screw drop prevention terminal according to an embodiment of the present invention. The screw drop prevention terminal 21 according to the present invention includes a terminal base 22 formed of an electrically insulating material, a terminal fitting (described later) attached to the terminal base 22, and a terminal screw holder 23 also formed of an electrically insulating material. And terminal screw 24. M is an electronic watt hour meter.

FIG. 2 is a perspective external view showing a state in which the terminal base 22 and the terminal screw holder 23 are also separated from each other.

FIG. 3 is an embodiment of the present invention, a screw drop prevention terminal
FIG. 4 is a plan view of a terminal base portion 22 and a terminal fitting 25 of FIG. 21, and FIG. 4 is a sectional view of the screw drop prevention terminal 21 of the same. In addition,
In FIG. 4, one of the two terminal rows is shown as a sectional view when the terminal screw holder 23 is removed from the terminal base portion 22.

As shown in FIGS. 1 to 3, the terminal base 22 has a plurality of terminal fittings 25 (in this embodiment, seven terminal fittings 25 are arranged in two rows, for a total of 14 pieces). The terminal base 22 is separated by 26 and is molded and provided in the terminal base 22 formed of an electrically insulating material.

FIG. 5 is an embodiment of the present invention, a screw drop prevention terminal
It is a figure which shows the terminal screw holder 23 of 21. The figure (a) is a top view, the figure (b) is a back view, the figure (c) is the figure (a).
6A is a cross-sectional view taken along the line AA, and FIG. 6D is a cross-sectional view taken along the line BB in FIG.

FIG. 6 is a detailed view of the female screw hole 27 of the terminal screw holder 23 shown in FIG. 5 into which the head of the terminal screw 24 is screwed.

FIG. 7 is an embodiment of the present invention, a screw fall prevention terminal
21A and 21B are views showing the terminal screw 24 of FIG. 21, in which FIG. 11A is a plan view and FIG.

8 (a) shows a state in which the crimp terminal 28 is about to be inserted into the pressure contact position of the terminal fitting 25, and FIG. 8 (b).
Shows a state in which the crimp terminal 28 is pressed.

An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the screw cap prevention terminal 21 of the present invention is
A terminal screw holder 23 is attached to the terminal base 22 for use. As shown in FIGS. 4 and 8, the terminal screw holder 23 has a notch at both ends of the head of the partition wall 26 of the terminal base 22.
The engaging projection 30 of the terminal screw holder 23 is firmly attached to the 29 so as to engage with each other.

As shown in FIG. 7, the terminal screw 24 has a male screw portion 31 for pressing the crimp terminal 28 to the terminal fitting 25 at its lower portion, and also has a male screw portion 32 on its head. When the terminal screw 24 is loosened from the terminal fitting 25, the male screw portion 32 formed on the head of the terminal screw 24 has a female screw hole 27 in the terminal screw holder 23 shown in FIGS. 4 to 6 and 8. Screw together.

A spring washer 33 and a flat washer 34 are attached to the terminal screw 24 so that the crimp terminal 28 is securely pressed against the terminal fitting 25 and the terminal screw 24 is not gradually loosened due to vibration or the like. There is.

As shown in Fig. 4, when the terminal is not used, the terminal screw 24
Is usually in a state in which the male screw portion 32 of its head is screwed and held in the female screw hole 27 of the terminal screw holder 23, and therefore,
Insert the crimp terminal 28 between the terminal metal fitting 25 of the terminal base 22 and the tip 35 of the terminal screw 24 held by the terminal screw holder 23 at the pressure contact position of the terminal metal fitting 25 as shown in the figure. A sufficient gap is formed in order to

As shown in detail in FIG. 6, the female screw hole 27 of the terminal screw holder 23 has a pitch of 1 pitch as shown in FIGS. It is formed by providing a ridge.

This is because the crimp terminal 28 is pressure-welded, so that when the terminal screw 24 is screwed in, the greater the downward displacement of the terminal screw 24 per screw rotation, the better the workability. By forming the pitch of the male screw portion 32 of the head of the terminal screw 24 to be slightly larger than the male screw portion 31 of the lower portion of the terminal screw 24 and screwing the terminal screw 24, the male screw portion 31 of the lower portion of the terminal screw 24 becomes the terminal. While engaging with the female screw portion 36 of the metal fitting 25, and while the male screw portion 32 of the head of the terminal screw 24 is screwed into the female screw hole 27 of the terminal screw holder 23, molded with an electrically insulating material such as synthetic resin. The internal screw hole 27 of the terminal screw holder 23 is elastically deformed to withstand this.

The connection of the crimp terminal 28 to the terminal fitting 25 by pressure contact with the terminal screw 24 is performed by connecting the crimp terminal 28 crimped to the end of the electric wire to the tip portion 35 of the terminal screw 24 as shown in FIG. 8 (a). It is easily carried out by inserting the terminal screw 25 from the side in the pressure contact position of the terminal metal fitting 25 in the gap between the terminal metal fitting 25 and the terminal metal fitting 25 and screwing the terminal screw 24 with a driver (not shown). As shown in FIG. 8 (b), before the crimp terminal 28 is completely pressed against the terminal fitting 25,
The male screw part 32 on the head of the terminal screw 24 is
It is released from the screw engagement with the female screw hole 27 of.

When the male screw portion 31 of the terminal screw 24 is screwed into the terminal fitting 25 without pressing the crimp terminal 28 or when the crimp terminal 28 already connected is removed, loosen the terminal screw 24, Eventually, the male screw portion 32 of the head of the terminal screw 24 begins to be screwed into the female screw hole 27 of the terminal screw holder 23, and if the terminal screw 24 is continued to be loosened as it is, the male screw portion 32 of the head of the terminal screw 24 and the terminal screw The female screw hole 27 of the holder 23 is elastically deformed and screwed, and the male screw portion 31 of the lower portion of the terminal screw 24 is connected to the terminal fitting 25.
When the terminal screw 24 is disengaged from the female thread 36 of the terminal screw and the terminal screw 24 is continued to be loosened, as shown in FIG. 4 and FIG.
The external thread 32 of the head of the
By being screwed and held without being elastically deformed, a sufficient gap is formed between the tip end portion 35 of the terminal screw 24 and the terminal fitting 25 so that the crimp terminal 28 can be inserted into and removed from the pressure contact position.

In this way, according to the screw drop prevention terminal 21, the terminal screw 24
Without removing the screw from the screw drop prevention terminal 21.
28 can be connected and disconnected.

In the screw drop prevention terminal 21 according to the present invention, the terminal screw 24 is removed from the terminal metal fitting 25, that is, the terminal screw 24 is screwed and held by the terminal screw holder 23 at the time of manufacture and shipment by the manufacturer. Therefore, on the user side, it is not necessary to remove the terminal screws 24 from the terminal fittings 25 at the time of connection, and the connection work can be made efficient.

Also, the terminal screw holder 23, which is a feature of the embodiment of the present invention,
Not only holds the terminal screw 24 and prevents it from falling off, but also covers the terminal metal fitting 25 and the partition wall 26 to prevent foreign matter such as dust or liquid from adhering to the terminal metal fitting 25 important for the terminal. It also contributes to prevent

Further, instead of the engaging protrusion 30 of the terminal screw holder 23, the engaging portion 37 is formed by bending the lower end portion of the side surface of the terminal screw holder 23 inward as shown in FIG. You may do it.

(Effects of the Invention) As described above, according to the present invention, the screwing with the terminal fitting and the screwing with the female screw hole of the terminal screw holder are continuously performed by rotating the terminal screw in the loosening direction. Since the terminal screw is held by the terminal screw holder when the terminal screw is removed from the terminal fitting, the terminal screw can be prevented from coming off economically with a very simple structure. In addition, the screw pitch of the male screw part of the head of the terminal screw is made larger than the screw pitch of the terminal screw, and the female screw of the female screw hole of the terminal screw holder is one pitch and is elastically deformable. Due to the difference, the stress applied to the female screw hole is absorbed by the elastic deformation of the female screw. Therefore, when the male screw part of the terminal screw head is screwed into the female screw hole of the terminal screw holder, The amount of displacement can be increased to improve workability.

[Brief description of drawings]

FIG. 1 is a perspective external view of an electronic watt-hour meter equipped with a screw cap prevention terminal according to an embodiment of the present invention, and FIG. 2 is a state in which the terminal base of the screw cap prevention terminal and a terminal screw holder are also separated. Fig. 3 is a plan view of the terminal base portion of the screw cap prevention terminal, Fig. 4 is a sectional view of the screw cap prevention terminal, and Fig. 5 is an external view and sectional view of the terminal screw holder. FIG. 6 is a detailed view of the female screw hole of the terminal screw holder, FIG. 7 is an external view of the terminal screw, FIG. 8 is a sectional view of the screw drop prevention terminal, and FIG. 9 is another embodiment of the present invention. Sectional views, FIG. 10 and FIG. 11 are views showing an example of a conventional screw dropout prevention terminal. 21 …… Screw captive terminal, 22 …… Terminal base, 23 …… Terminal screw holder, 24 …… Terminal screw, 25… Terminal fitting, 26 ……
Partition wall, 27 ... Female screw hole of terminal screw holder, 28 ... Crimping terminal, 29 ... Notch, 30 ... Engaging protrusion, 31 ... Male screw part, 32 ... Male screw part, 35 ... Tip part, 36 ...... Female thread part,
37 ... Engagement part.

Claims (1)

[Scope of utility model registration request] 1. A terminal provided with a terminal fitting and a terminal screw screwed into the terminal fitting, wherein a male screw portion having a screw pitch larger than a screw pitch of the terminal screw is formed on a head portion of the terminal screw. Forming a female screw hole having an elastically deformable female screw for one pitch, which is screwed to a male screw portion of the head of the terminal screw, in a terminal screw holder attached to the terminal so as to cover the terminal metal fitting above; The position of the relative relationship between the female screw hole of the terminal screw holder and the terminal metal fitting is set such that the terminal screw is in both the terminal metal fixture and the female screw hole of the terminal screw holder in the process of removing the terminal screw from the terminal metal fitting. A screw drop prevention terminal characterized by being set to be in a screwed state.